druid-vulnerability-fix

name	druid-vulnerability-fix
description	How to fix the Apache Druid JavaScript sampler vulnerability. Use this skill when patching Druid code to block arbitrary JavaScript execution.

Druid JavaScript Sampler Vulnerability Fix

Overview

The vulnerability allows authenticated users to execute arbitrary code via the /druid/indexer/v1/sampler endpoint by passing a malicious JavaScript payload with an empty key "" in the JSON spec.

Fixing Strategy

1. Identify the affected component: The JavaScriptConfig or related validation logic in Druid's processing module is responsible for the JavaScript filter.
2. Restrict access: Ensure that the JavaScript filter is properly guarded and cannot be bypassed by empty keys or other malformed JSON structures.
3. Validate payload: Add strict validation to the sampler configuration that prevents arbitrary code injection via the function property.

Patching Workflow

1. Locate the responsible class (likely JavaScriptFilter or JavaScriptConfig).
2. Implement robust input sanitization and validation.
3. Generate a diff/patch file in /root/patches/.
4. Apply the patch to /root/druid/.